Role of cell regularity and relative density on elastoplastic compression response of 3-D open-cell foam core sandwich structure generated using Voronoi diagrams

The Voronoi tessellation technique in a 3-D space is used for modeling the structural foam core used in sandwich configurations. The procedure involves stochastic generation of nuclei in a control volume. The level of randomness of the microstructure is controlled with a simple sequential inhibition (SSI) process and quantified using a regularity parameter. The influence of the cell regularity on the compression response of open-cell microstructures is studied in the elastic and plastic deformation regimes. Additionally, the effect of relative density is analyzed for different regularities and results are compared with available analytical and semi-empirical models. The low probability of generating highly regular structures using the SSI process has led to the development of a perturbation approach to complement the SSI methodology. Models for estimating elastoplastic properties based on the density of the foam and the regularity parameter are presented. Simulations suggest a monotonic and direct relationship between mechanical properties and the regularity parameter for the entire range of strains considered.